1. Field of the Invention
The present invention relates to data transcription systems and, more particularly, to a data transcription system for transferring previously recorded data, such as seismic data, contained in one medium to a second medium and which has data processing capabilities.
2. Setting of the Invention
In seismic exploration, energy is imparted to the surface of the earth and the resulting energy waves travel through the earth and are reflected by subsurface interfaces. These reflected waves return to and are detected at the surface by geophones or other various vibration sensors. The output of each of these geophones is then recorded by specialized recording equipment, such as magnetic tape recorders, for later processing, plotting, and evaluation.
Often the specialized data recording equipment includes adjustable signal filtering circuitry and gain control circuitry which are adjustable by the operator prior to the recording of the seismic data. Such equipment is disclosed in U.S. patent application Ser. No. 454,405 filed Dec. 29, 1982, and which is incorporated herein by reference. The filter and gain control settings which are chosen by the operator may not be the optimum settings for a certain geological area, but this is not known until after the seismic data has been acquired, processed, plotted and analyzed. If this is the case, the geological area may have to be resurveyed at additional expense and loss of time. There exists a need for a recording device which includes processing capabilities so the operator can record a seismic trace, process it using different filter and gain settings, and evaluate the best combination of settings prior to conducting a full survey of the geological area.
Once the seismic data has been recorded, processed and plotted, sometimes it becomes apparent that one or more of the geophones or recording equipment itself are not operational or not operating within necessary specifications. In this case, the geological area may have to be resurveyed at additional expense and loss of time. There exists a need for a recording device which, in the field, detects and attempts correction of such data errors so corrective action can be taken while the survey crew is still in the geological area. Illustrative of the broad concept of data error correction in seismic operations is U.S. Pat. No. 3,496,528.
One type of data recording equipment used in seismic exploration is called a seismometer group recorder (SGR) which was developed by Amoco Production Company and covered by U.S. Pat. No. 3,806,864 (which is herein incorporated by reference) and the previously mentioned U.S. patent application Ser. No. 454,405. In an SGR, the seismic data is recorded on magnetic tape cartridges or solid state memory devices. At the end of a day's surveying, the individual cartridges are removed from the SGR's and are transcribed onto a different medium, such as 9-track magnetic tape, for processing. Or, the individual solid state memory devices are connected to a transcriber unit for outputting onto a different medium, such as 9-track magnetic tape, for processing. Thereafter the 9-track magnetic tape is transferred to a computing facility for processing. In many situations it is desirable to process, plot and evaluate the seismic data as soon as possible so any needed corrective action to the survey methods or location can be taken as rapidly as possible. However, when surveying in remote locations, this transfer of the 9-track magnetic tape to a processing facility can take several days. There exists a need for a field transcriber system capable of performing certain quality control and processing functions and transcribing seismic data from different mediums onto a second medium, and also to transfer quickly this data via radio or satellite communications link to a processing facility.
Various electronic devices have been developed for transcribing data from one medium to a second medium. One simple example of this is a cassette tape recording system where a previously recorded signal on one cassette is recorded onto a blank cassette. This system obviously does not have the desired and necessary control and processing capabilities as described above.
Other devices have been developed for transcribing previously recorded data, such as stored on punch cards, to another medium, such as magnetic tape. A device of this type is illustrated by Great Britain Pat. No. 1,356,990. Such a device, however, does not have the desired and necessary control and processing capabilities as described above.
In the art of seismic data transcription, U.S. Pat. Nos. 3,159,808 and 3,588,911 are illustrative of seismic plotting devices used to transcribe seismic data in analog form from magnetic tape storage to a plotter. These devices are used only for plotting seismic data and are not data transcription devices as contemplated by the inventors hereof and does not have the desired and necessary control and processing capabilities as described above.